The overall objective of this investigation is to clarify and characterize the relationship between metabolic regulation and organ function in animals under in vivo conditions. In the course of studying metabolic alterations that occur during various forms of experimentally produced shock, attention is directed to the hormonal derangement that takes place in the syndrome and also to reproduce the in vivo changes in an in vitro system. Thus, the proposed studies deal primarily with hormonal changes and their importance in determining reversibility of shock and also with some of the metabolic alterations that were observed under in vivo conditions in an in vitro system.